8 April 1997 Contract OPP 89-22832
Office of Polar Programs
National Science Foundation
4201 Wilson Blvd., Suite 755S
Arlington, VA 22230
Attention: Mr. Frank Brier, Facilities Engineering Project
Manager
Subject: INPUT FROM THE SOUTH POLE SCIENTISTS ON THE SPSM
ELECTRONICS SYSTEMS CONCEPTS REVIEW
Per your request at the recent South Pole Station Modernization
(SPSM) Electronics Systems Concepts Review Meeting (Allied Signal,
26-27 March 1997), attached please find input on the topics that ASA
was tasked to obtain from South Pole scientists. ASA edited their
input only slightly, to include in ALL CAPS the pertinent reference
paragraph(s) in the Allied Signal document "Amundsen-Scott South
Pole Station Redevelopment Project: Electronic Systems Major
Systems Concepts, Definition, and Evaluation".
This input reflects coordination of the scientists' responses by Dr.
Robert Morse, Chair of the South Pole Users Committee (SPUC) and
Dr. Robert Loewenstein, Chair of the Communications and Computing
Working Group in the SPUC. They contacted and collated responses
from the following South Pole scientists: Bill Trabucco, Tony
Fraser-Smith, Pat Mock, George Papen, Tony Stark, Ellen
Mosley-Thompson, Gonzalo Hernandez, and Ted Rosenberg, plus
themselves.
ASA thanks all of the South Pole scientists for their input on the
SPSM Electronics Systems topics on such short notice and looks
forward to their continuing participation in the ongoing
discussions of the SPSM Project.
Please request any further information required.
Steven T. Kottmeier
ASA Chief Scientist
Attachment (1)
As Stated
cy: C.W. Sullivan, NSF/OPP Director
E. Chiang, NSF/OPP Section Head, Polar Research Support
D. Peacock, NSF/OPP Section Head, Antarctic Sciences Section
J. Lynch, NSF/OPP Aeronomy and Astrophysics Sciences Program
Manager
D. Bresnahan, NSF/OPP Systems Manager
S. Stephenson, NSF/OPP Research Support Manager
A. Brown, NSF/OPP Manager, Specialized Support
P. Smith, NSF/OPP Technology Development Manager
D. Tupick, NSF/OPP Electronics Systems Coordinator
J. Rand, NSF/OPP South Pole Engineering Projects Manager
J. Marty, NSF/OPP South Pole Construction/O&M Coordinator
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SOUTH POLE SCIENTISTS INPUT TO
SPSM ELECTRONICS SYSTEMS CONCEPTS REVIEW
8 April 1997
PARAGRAPH 3.3 GOES GROUND SYSTEMS IF0400
1. Acceptable EMI/RFI emissions. EMI susceptibility, EMI hardening
Dark Sector EMI/RFI thresholds
There is no magic number for EMI/RFI.
Every experiment will have its own requirements and should be
treated on a case by case basis. The fact that most existing
experiments were able to successfully work with the meteor-trail
radar in operation indicates that most current experiments are not
particularly EMI sensitive.
We cannot speak for all possible future experiments, but as a
general policy, emissions from the new station should be kept as
spectrally clean as possible using reasonable and moderate cost
precautions. Any over-specification would be a waste of resources.
The design discussion should focus on the noise derived from power
lines, which will be the primary polluter.
One note: The antennas for satellite communications at frequencies
between 1 GHz and 18 GHz should be designed for low spillover and
low sidelobes. This may require that these antennas be somewhat
more expensive than would otherwise be the case.
PARAGRAPH 3.7 SOUTH POLE TDRSS RELAY NETWORK IF1020
2. Projected Data Rates for TDRSS satellite relay network service,
multiple user (150 MHz)
We estimate that the data rates will grow to ~2 GByte/day over the
next five years. However, we should note that we are concerned
with more than just data rates. Connectivity, satellite
availability, and reliable interactive access via internet is, in
many ways, more important that super-high bandwidth,
non-interactive connection links.
No matter what bandwidth is achieved, new bandwidth intensive
technologies will eat it up. A good initial goal should be T3 for
both uplink and downlink. However, a clear upgrade path should be
included in the planning document from the initial design because
no matter what happens, people will need more bandwidth.
PARAGRAPH 3.6 ATS-3/LES-9 GROUND SYSTEM IF0880
3. Historic Record of Sky Temperatures ATS-3/LES-9 ground systems
No comment....
PARAGRAPH 3.12 GPS TIME RUBIDIUM FREQUENCY SYSTEM IF2020
4. GPS time-keeping. Should station provide? Centralized facility.
good idea or not? Experimenters to provide specifications. Accuracy
needed 10 ms, 1 ms, ...1 uS? Working Groups to suggest approaches.
There is no scientific need to create a station-wide timing system.
Having a station-wide time distribution system used to be a good
idea. GPS has now become so inexpensive, however, that a
distributed system seems pointless.
The best solution is a low cost, station-wide NTP (network time
protocol) added to the existing computer network. NTP will give
sub-millisecond absolute time accuracy for network computers.
Experiments needing time better than this should deal with it
themselves.
PARAGRAPH 3.15 METEOROLOGICAL SYSTEMS (FLIGHT SYSTEMS) IF2930
5. Science Meteorological Requirements --ASOS system beyond flight
operations
The standard met readings should be sufficient.
PARAGRAPH 3.1 HIGH FREQUENCY ANTENNA SYSTEM IF0110
6. EMI from HF antenna systems?
Again, look at on a case by case basis.
PARAGRAPH 3.19 CATV (VDS) SYSTEMS IF3640
7. CATV(VDS) Systems, CCTV (entertainment) in station Allows for
real time data acquisition
We doubt if this is necessary at all. Given the ubiquity in digital
systems, old analog systems will be obsolete for data displays. We
should think in terms of the descendents of web browsers: digitial
displays using LANs.
PARAGRAPH 3.13 CABLE PLANT DISTRIBUTION SYSTEM IF2300
8. What about Local Area Network (LAN) structures?
100 Mb/s backbone, with local subnets. No real change from the
committee's previous recommendations for the current station.
PARAGRAPH 3.3 GOES GROUND SYSTEMS IF0400
3.6 ATS-3/LES-9 GROUND SYSTEM IF0880
3.7 SOUTH POLE TDRSS RELAY NETWORK IF1020
9. What about "connectivity", which allows science to be done
"interactively", keeping the winter-over's emotionally connected
with the experimenters at the home institutions.
I quote from the 1996 SPUC report on Communications
1) 24 hour connectivity with the south pole.
a) Continuous communications would support remote observing
programs at the CARA facilities.
b) The AMANDA and SPASE collaborations could move much their
data analysis to machines at the pole, which would allow
results to be obtained much more quickly.
c) The window for interaction between CONUS and Pole will be
widened, resulting in much more efficient interaction with
winter-overs.
d) The longer availability would allow better use of CONUS
experts (such as software engineers).
2) Pursue acquisition of other satellites (GOES?) to complement the
two we use now.
3) Emphasize connectivity convenience, times, and quality rather
than very high bandwidth.
While we could obtain more bandwidth with TDRS, TDRS does not
provide the full-duplex connectivity described above. We think
our money will be better spent to increase the cadre of GOES
type satellites in the future and supply more bandwidth,
satellite availability and performance with interactive,
internet capable pathways.